Automatic stop for telegraph printer



Nov. 17, 1959 B. HOWARD ,91 17 AUTOMATIC STOP FOR TELEGRAPH PRINTERFiled Feb. 18, 1957 FIGZ FIGI JNVEN TOR. BERNARD HOWARD BY M; I

ATTORNEYS Unite AUTOMATIC STOP FOR TELEGRAPH PRINTER Bernard Howard,Ramsey, Nl, assignor to Teleprinter Corporation, Hackensack, N.J., acorporation of New Jersey Application February 18, 1957, Serial No.640,806

r 7 Claims- (Cl. 178-41) This invention relates to telegraph printers,and more particularly to an automatic stop mechanism for the same.

The primary object of the present invention is to generally improvetelegraph printers, and a more particular object is to provide anautomatic stop mechanism for the same. A still more particular object isto provide such a mechanism arranged for use with a telegraph printer ofthe general character shown in my Patent No. 2,769,029, granted October30, 1956, and entitled Telegraph Printer.

In telegraph printers, it is common to employ a local drive motor whichruns in synchronism with a like motor at the remote transmitter. Thisdrive motor operates much of the mechanism continuously even when nosignal pulses are being received, which increases the wear of themechanism. Moreover, in the case of portable equipment operated by abattery, it is wasteful of battery current.

To overcome this difficulty, I provide automatic stop mechanism whichstops the local motor and consequently all of the printer mechanism, ifno signal is received for a predetermined desired time. The motor andassociated mechanism are restarted, however, upon the reception of astarting signal pulse. The term pulse is here used broadly, and appliesto interruption of telegraph line current, because the usual practice isto maintain current on the line when no signal is being transmitted.(This insures discovery and recognition of a possible break in theline.) Thus, in the present case, the motor will be restarted andenergized by the local current source if the telegraph line current isinterrupted upon resumption of signalling. I

Another object of the invention is to make the predetermined non-signaltime which stops the motor, readily adjustable. In the present case, themechanism includes a scale and pointer which may be adjusted for anon-signal time ranging anywhere from one-half to two minutes. A stillfurther object of the invention is is provide multiple scales whichdiffer in length, and one or another of which maybe used, depending onthe rate of signal transmission.

To accomplish the foregoing general objects, and other more specificobjects which will hereinafter appear, my invention resides in thetelegraph printer and automatic stop elements, and their relation one toanother, as are hereinafter more particularly described in the followingspecification. The specification is accompanied by a drawing in which:

Fig. 1 is an edge view of an automatic stop mechanism embodying featuresof my invention;

Fig. 2 is a front elevation of the same;

Fig. 3 is a schematic wiring diagram explanatory of the invention;

Fig. 4 is a fragmentary vertical section showing the hammer shaft andmain cam shaft in one particular telegraph printer;

Patented Nov. 17, 1959 Fig. 5 shows how the present automatic stopmechanism is applied to such a printer; I

Fig. 6 is a fragmentary view showing a minor modification of themechanism; and

Fig. 7 shows a modified arrangement of telegraph printer embodying myinvention.

Referring to the draw n Fig. 4 is a vertical section corresponding tothe upper part of Fig. 13 in my aforesaid Patent No 2,769,029. Paper 194enters a paper slot at 192, and is fed upwardadjacent a type body T.This operatesthrough an inked ribbon 200 when the paper is struck by ahammer 196. The hammer 196 is normally retracted by a spring, exceptwhen operated by a hammer bar 212 carried by a hammer shaft 216. Thepaper 194 is moved by means of a feed drum 202, and thence around aroller 204, and upward at 206.

The shaft is a main cam shaft which is driven by the local motor of thetelegraph printer. The motor is not shown in Fig. 4, but is indicated atM in Fig. 3. It will be understood that shaft 90 is a continuouslyrotating shaft, whether or not a signal is received, while the hammershaft 216 oscillates only upon receipt of a signal.

Referring now to Fig. 2, the continuously rotating shaft is indicated at90, while the intermittently oscillated shaft is indicated at 216. Thestop mechanism includes speed reduction gearing driven by shaft 90 andtherefore by the motor, and terminating in a movable means 12, 34controlled bya releasable clutch 14 to operate a switch 16. There isalso a resilient restoring means 18 urging the movable means 12 in adirection oppositeto that in which it is urged by the motor and shaft90.

Considered more specifically, the speed reduction means includes a worm20 driving a worm gear 22which drives a pinion 24 meshing with a gear26. The latter drives a pinion 28 meshing with a gear 30. The latterdrives a friction wheel 34. The movable means 12 is a strip or linkwhich is connected to an operating finger 36 pivoted at 38. This fingerwhen moved down by the link 12 operates the switch 16. The switch 16ispreferably a sensitive precision switch, a common commercial exampleof which is the so-called Microswitch.

The clutch 14 is simply a pressure roller which presses the link 12,against the friction roller 34. The pressure roller 14 is carried on onearm 40 of an angle lever which is pivoted at 41, and the other arm 42 ofwhich projects beyond the frame 44. Roller 14 is urged against link 12by a pull spring 46 connected to arm 42. The latter is disposed in thepath of movement of an operating finger 50 (Figs. 2 and 5), the hub 52of which is mounted on the hammer shaft 216 (Figs. 2 and 5).

The link 12 is preferably frictionally surfaced. The frictional surfaceis needed on only one side, that which engages the friction drive roller34, but in practice it may be frictionally surfaced on both sidesbecause it is convenient to make the same by dipping a thin metal stripin a liquid rubber compound or similar frictional I material.

Referring now to Fig. 3 of the drawing, the incoming signal is receivedover conductors connected to a relay coil 152 which operates a relayarmature 154 between contacts 156 and 158. When the relay is energized,a circuit is established from a local power supply source throughcontact 156 to the left-hand magnets at 2, 3, 4 etc. When the relay isde-energized, a circuit is established from local source 160 throughcontact 158 through the righthand magnets. These magnets controltheprinter in a manner which is explained in detail in my aforesaidPatent 2,769,029.

In accordance with the present invention, I provide a circuit across theline 150, that is, in shunt with the relay coil 152. This circuitincludes the aforesaid switch 16 and a relay magnet 54 controllingcontacts 56 which are normally closed, as indicated by spring 58. Thecontacts 56 are disposed in the circuit 60, 62 leading from local powersupply 160 to the motor M.

The switch 16 is normally open, and thus the relay 54 is not affected bythe pulsing of the signal circuit 150. However, if the transmission ofsignals is interrupted for a substantial period of time, the link 12(Fig. 2) is pulled downward until the operating finger 36 reaches andoperates switch 16. This closes the switch, and inasmuch as the signalline 150 is in normally-energized condition, the relay 54 is operated,thereby opening contacts 56 and stopping the motor M. The motor remainsstopped until signalling is resumed by means of a long starting pulse orinterruption.

During normal signalling, the motor is not stopped because the switch 16is open. Referring to Fig. 2, switch 16- remains open because theoperating finger 36 cannot reach the switch 16. It keeps beginning tomove down, but the incoming signals cause operation of the hammer shaft216 each time a letter is printed, and this moves the pressure roller 14away, whereupon restoring spring 18 pulls the link 12 and operatingfinger 36 upward to their starting point. In practice, the parts vibraterapidly and almost imperceptibly, and it is only when there is nooperation of the shaft 216 for a desired relatively long period of timethat the slowly turning friction wheel 34 has an opportunity to move thelink 12 and with it the operating finger 36 far enough to affect theswitch 16.

The time required before stopping the motor is readily adjustable. Forthis purpose, the upper or starting position of the operating finger 36is determined by an adjustable pointer 64, pivoted at 38, and locked inposition by suitable means, in this case, a thumb nut 66. In theparticular case here shown, the pointer is movable over a scale plate68' provided with an arcuate slot 70 through which the lock screwpasses. The pointer cooperates with a scale 72. In the present case,this scale is marked from /2 to 2, representing a time duration of one ihalf minute to two minutes. By loosening the thumb nut 66 and moving thepointer 64 to a desired position on the scale, the non-signal timerequired for shutdown is readily adjusted.

However, the non-signal signal transmission rate, because thatdetermines the speed of rotation of the main cam shaft 90. A number ofdifferent signal transmission speeds have been standardized. Forexample, the American standard is 60 words per minute, the Europeanstandard is 66 words per minute, and a high-speed rate which has comeinto use is 100 words per minute. The scale plate 68 is accordinglyprovided with two additional scales 74 and 76. In the particular casehere illustrated, the scales 72, 74 and 76 correspond respectively to100, 66 and 60 words per minute.

Referring now to Fig. 5 of the drawing, the main cam shaft is indicatedat 90, and the hammer shaft is indicated at 216. These correspond to thesame shafts shown in Fig. 4, and to the corresponding shafts shown inFig. l3 of my Patent 2,769,029. The finger 50 is mounted on hammer shaft216 and engages arm 42 of the angle lever which carries the pressureroller 14 (Fig. 2). Worm 20 (Fig. 5) meshes with worm gear 22', thusturning a shaft 23 which drives the train of reduction gearing withinframe 44, as already described in connection with Fig. 2. Frominspection of Fig. 5, it will be understood that each counter clockwiseoscillation of shaft 216 to cause the printing of a letter, raises thearm 42 and releases the pressure roller 14 (Fig. 2), and so restores theoperating finger 36 to initial position.

The mechanism maybe operated equally well by a downward motion, and Fig.6 shows a slight modification of the mechanism shown in Fig; 2. Much ofthe mechanism has been omitted in Fig. 6, to simplify the drawing, butbriefly, the operating finger 80 and link 82 are moved time is itselfrelated to the down by a friction roller 84 and a pressure roller 86.The latter is carried on an angle lever pivoted at 88. This pivot isbelow the pressure roller 86, instead of above as shown in Fig. 2. Thepressure roller is therefore released by downward movement of the fingerbearing against the arm 102 of the angle lever.

In Fig. 4, the printer is shown in upright position, as in my aforesaidUS. Patent 2,769,029. However, the printer may be disposed in horizontalposition as illustrated in my copending application Serial No. 596,294,filed July 6, 1956, and entitled Telegraphic Printing Apparatus. Such ahorizontal arrangement is shown in Fig. 7 of the drawing, whichcorresponds generally to Fig. 11 of said copending application. In Fig.7, paper 104 is taken from a paper roll 106 and fed downward over aguide roll 108 to a feed roll 110. The latter cooperates with a pressureroll 112. The paper then moves upward out of the printer as shown at114. In its upward movement, it passes between a type wheel or cylinder116, and a ribbon 118. The latter is struck by a hammer which isoperated by a hammer shaft 122. The latter also carries the finger 100bearing against one arm 102 of the angle lever which carries thepressure roller of the automatic stop mechanism. The arms 100 and 102correspond to the similarly numbered parts in Fig. 6.

The automatic stop mechanism is mounted on a frame 124, and is driven bymeans of a worm 126 mounted on the main cam shaft 128, or on any othershaft which is continuously driven by the driving motor of the printer.The worm 126 meshes with a worm gear 130 which in turn drives thereduction gearing and friction roller in the automatic stop unit 124.These parts may correspond exactly to those already described inconnection with Figs. 2 and 5.

The initial starting signal from the transmitter should be a longer thannormal pulse (opening of'the line circuit). It should be longer than thetime needed for a printed character, in order to produce an operation ofthe hammer shaft, for it is the latter which releases the clutch andlink.

. It will be understood that the shaft which keeps releasing the stopmechanism need not necessarily be a hammer shaft. Any intermittentlymovable part or vibrated part may be used for this purpose. Theimportant thing is that, unlike the main shaft or cam shaft whichrotates continuously, it should bea part which works only in response tothe reception of signals.

It will also be understood that while I have shown the operating finger36 moved downward and restored upward by means of a restoring spring 18,the operating finger may be pulled upward by link 12, and fall back toinitial position gravitationally. The spring arrangement is preferred,but a gravitational arrangement is operable.

It is believed that the construction and method of operation of myautomatic stop for telegraph printer, as well as the advantages thereof,will be apparent from the foregoing detailed description. It will alsobe apparent that while I have shown and described my invention inseveral preferred forms, changes may be made 'in the structures shownwithout departing from the scope of the invention as sought to bedefined in the following claims.

I claim:

1. Automatic stop mechanism for a telegraph printer having a drivingmotor which operates continuously with or without incoming signals, anda reset part which opcrates only in response to incoming signals, saidstop mechanism including speed-reduction gearing driven by said motorand terminating in a movable means controlled by a releasable clutch tooperate a switch, resilient restoring means urging the movable means ina direction opposite to that inwhich it is urged by the motor, circuitryincluding the aforesaid switch such that move- "may ment of the movablemeans for a predetermined desired time operates the switch and stops themotor, and means connecting the aforesaid reset part to said clutch torelease the same in response to substantially any incoming signal.

2. Automatic stop mechanism for a telegraph printer having a drivingmotor which operates continuously with or without incoming signals, anda reset part which operates only in response to incoming signals, saidstop mechanism including speed-reduction gearing driven by said motorand terminating in a friction wheel, a link connected to an operatingfinger to operate a switch, a pressure roller to press the link againstthe wheel, restoring means to urge the link in a direction opposite tothat in which it is rolled by the wheel, circuitry including theaforesaid switch such that movement of the link and finger for apredetermined desired time operates the switch and stops the motor, andmeans connecting the aforesaid reset part to said pressure roller tomove the same away from the link in order to release the link inresponse to substantially any incoming signal.

3. Automatic stop mechanism for a telegraph printer having a drivingmotor which operates continuously with or without incoming signals, andan oscillatable print hammer shaft which operates only in response toincoming signals, said stop mechanism including speed-reduction gearingdriven by said motor and terminating in a friction wheel, a frictionlink connected to an operating finger to operate a switch, a pressureroller to press the link against the wheel, resilient means urging thelink in a direction opposite to that in which it is rolled by the Wheel,circuitry including the aforesaid switch such that movement of the linkand finger for a pre determined desired time operates the switch andstops the motor, and means connecting the print hammer shaft to saidpressure roller to move the same away from the link in order to releasethe link in response to an incoming signal.

4. Automatic stop mechanism for a telegraph printer having a drivingmotor which operates continuously with or without incoming signals, andanother part which operates only in response to incoming signals, saidstop mechanism including speed reduction gearing driven by said motorand terminating in a friction wheel, a link connected to an operatingfinger to operate a switch, a pressure roller to press the link againstthe wheel, restoring means to urge the link in a direction opposite tothat in which it is rolled by the wheel, circuitry including theaforesaid switch such that movement of the link and finger for apredetermined desired time operates the switch and stops the motor, andmeans connecting the aforesaid part to said pressure roller to move thesame away from the link in order to release the link in response tosubstantially any incoming signal a, normally stationary but adjustablepointer, said pointer having means acting as a stop for said finger whenthe link is released, whereby the non-signal time after which the motoris stopped is readily adjustable by movement of said pointer.

5. Automatic stop mechanism for a telegraph printer having a drivingmotor which operates continously with or without incoming signals, andanother part which operates only in response to incoming signals, saidstop mechanism including speed reduction gearing driven by said motorand terminating in a friction wheel, a link connected to an operatingfinger to operate a switch, a pressure roller to press the link againstthe wheel, restoring means to urge the link in a direction opposite tothat in which it is rolled by the wheel, circuitry including theaforesaid switch such that movement of the link and finger for apredetermined desired time operates the switch and stops the motor, andmeans connecting the aforesaid part to said pressure roller to move thesame away from the link in order to release the link in response tosubstantially any incoming signal, a fixed scale plate and a normallystationary but adjustable pointer cooperating with said scale plate,said pointer having means acting as a stop for said finger when the linkis released, whereby the non-signal time after which the motor isstopped is readily adjustable by movement of said pointer relative tosaid scale plate, said scale plate having a plurality of dilferentlydimensioned scales corresponding to different rates of signaltransmission with their corresponding difr'erent motor speeds.

6. Automatic stop mechanism for a telegraph printer having a drivingmotor which operates continuously with or without incoming signals, andan oscillatable hammer shaft which operates in response to substantiallyall incoming signals and only in response to incoming signals, said stopmechanism including speed reduction gearing driven by said motor andterminating in a friction wheel, a friction link connected to anoperating finger to operate a switch, a pressure roller to press thelink against the wheel, resilient means urging the link in a directionopposite to that in which it is rolled by the wheel, circuitry includingthe aforesaid switch such that movement of the link and finger for apredetermined desired time operates the switch and stops the motor, andmeans connecting the hammer shaft to said pressure roller to move thesame away from the link in order to release the link in response tosubstantially any incoming signal, a fixed scale plate and a normallystationary but adjustable pointer cooperating with said scale plate,said pointer having means acting as a stop for said finger when the linkis released, whereby the non-signal time after which the motor isstopped is adjustable by movement of said pointer relative to said scaleplate.

7. Automatic stop mechanism for a telegraph printer having a drivingmotor which operates continuously with or without incoming signals, andan oscillatable hammer shaft which operates in response to substantiallyall incoming signals and only in response to incoming signals, said stopmechanism including speed reduction gearing driven by said motor andterminating in a friction Wheel, a friction link connected to anoperating finger to oper ate a switch, a pressure roller to press thelink against the wheel, resilient means urging the link in a directionopposite to that in which it is rolled by the wheel, circuitry includingthe aforesaid switch such that movement of the link and finger for apredetermined desired time operates the switch and stops the motor, andmeans connecting the hammer shaft to said pressure roller to move thesame away from the link in order to release the link in response tosubstantially any incoming signal, a fixed scale plate and a normallystationary but adjustable pointer cooperating with said scale plate,said pointer having means acting as a stop for said finger when the linkis released, whereby the non-signal time after which the motor isstopped is adjustable by movement of said pointer relative to said scaleplate, said scale plate having a plurality of difierently dimensionedscales corresponding to different rates of signal transmission withtheir corresponding different motor speeds.

References Cited in the file of this patent UNITED STATES PATENTS2,344,792 Swezey Mar. 21, 1944 2,640,873 Moebius June 2, 1953 2,728,811Gemmel Dec. 27, 1955

